Automatic train control system



Sept. 20, 1932- w. H. REICHARD AUTOMATIC TRAIN CONTROL SYSTEM Filed July14, 1928 INVENT R'. Wade H. fiemhard. 724W? his ATTORNEY Patented Sept.20, 1932 UNITED STATES PATENT v OFFICELVTJYLG WADE H. REIoHARnornocrmsrnn, NEW YoRK, Assreuon To GENERAL. RAILWAY SIGNAL COMPANY, orROCHESTER, NEW YORK AUTOMATIC TRAIN ooivrnon SYSTEM Application filed my14, 1928. Serial No. 292,654.

Thisinvention relates to automatic train control systems, and moreparticularly to .electroepneumatic car-carried apparatus for suchsystems. I I

In a train control system of the contlnuous inductive type, to which thepresent invention is more particularly applicable, it is necessary toprovide against restrictions 1mposed due to a train passlng overcross-overs,

the permissive type, such as the proposed system, where the train mayproceed 1n response to the manifestation of vigilance by the engineer,by operating a suitable acknowledging device, it is proposed to requiresuch acknowledgment at repeated time intervals as determined by apneumatic time measuring apparatus. p

More specifically it is proposed in accordance with the presentinvention to sound an audible signal a predetermined period oftime'after a train has entered adverse territory, this interval of timebeing such that the audible signal is not sounded when atrain passesover a dead sectioni, to sound thisaudible signal for a predeterminedperiod' oftime thereafter, to impose an automatic brake application ifthe engineer has not manifested his vigilance during the sounding ofsaid audible signal, and to measure these intervals of time by pneumaticapparatus which depends for their proper functioning upon the venting offluid pressure from reservoirs of predetermined capacities throughrestricted openings of a predeterminedsiz'e. Further, it is proposed torequire the act of acknowledgment to take place after repeated timeintervals which are measured by a similar pneumatic apparatus.

Other objects, purposes and characteristic features of the invention arein part obvious from the drawing and will in part be pointed out in thespecification hereinafter.

In describing the inventionin detail reference will be made to theaccompanyingsingle sheet of drawing, in which the car-carried andtrackway apparatus ofv a train control system embodying the presentinvention hasbeen conventianally illustrated.

Y 'Traclcwa apparatus For the purpose of illustrating a complete systemthe simplified trackway apparatus of a portion of the system has beenillustrated, which includes the track rails divided into blocks byinsulating joints 2, of which the block I and the adjacent ends of twoother blocks H and J have been shown. Since 1, the various blocks inautomatic signal territory are the same it is deemed suflicient todescribe the parts of certain blocks only, and

like parts of other blocks have been assigned like reference charactershaving distinctive exponents. At the entrance of each of these blocks ispreferably provided a suitable wayside signal Z, which may be of -anysuitable construction, and has been illustrated as comprlsing asemaphore signal. These Sig-- nals are controlled by track circuitsinthe .usual manner, and the control apparatus therefore, except saidtrack circuitshas for convenience been omitted. Each of the blocksincludes the usual track battery3 and the usualtrack relay T. Atransformer 4 is preferably connected in series with each of the trackbatteries 3 for the pur'posefof superimposing upon the direct currentsup- Oar-carried apparatus On the car is contained a suitable polyphaserelay CR, which has one of its Windings 10 connected to the windingof-one car element 11, and has its other winding 12 connected to thewinding of another car ele-- by the amplifier A.

ment 13 through a suitable amplifier A. By this arrangement current iscaused to flow in one winding of the relay in accordance with the flowof current in one rail of the track, and current is caused to flow inthe other winding of the relay in accordance with current in the otherrail of the trackway, these currents being however amplified Suitablemeans is also preferably provided whereby the currentin one of thewindings of the relay is caused to be displaced in phase with respect tothe cur rent of its corresponding car element so that a displacement ofphase in the currents flowing in the main or control relay CR will rsult when the current flow in the two track rails are in phase, this inorder to produce a torque in the main or control relay CR, which ispreferably a relay of the inductive type'and requires suchphasedispiacement to obtain the best results.

The car-carried apparatus also includes an electro-pneumatic valve EPV,a pneumatic relay PR, a pneumatic brake valve PBV, an

Operation Function of the main relay. The main or control relay CRassumes its normal right hand position in which it has been shown whenthere is current flowing in the track rallsahead of the train toward thetrain 1n one rail through the axles of the train and away from the trainin the other rail, thereby energizing the electro-pneumatic valve EPV 7.through the following circuit: beginning at the terminal B of asuitable source of elec tric energy such as a battery, wire 20, contact21 of the main or control relay CE, wires 22, 23 and 24, normally closedcontact 25 of the reset switch RS, wire 26, winding of the EPV, wires 27and 28, contact 29 of the air switch SAS, wire 30 to the common returnwire C connected to the other side of said battery.

If there is no alternating current flowing in the track rails, possiblybecause the contacts 8 of the track relay ahead are open, the

track circuit is occupied another train ahead or the like, or thecurrent flowing therein is too small to operate the relay CR, this relaywill assume its de-energized con- .dition. If desired, the relay may becaused to operate to the left hand dotted position in response to thecurrent flowing in the same direction in both track rails to obtain someenergized and the electric acknowledging valve EAV is energized; It isnot deemed necessary to describe specific train movements in describingthe operation of the system, it being sufficient to point out how theapparatus functions under different conditions of energization of themain relay CR.

Dear sections. It is noted that with the electropneuinatic valve EPVenergized, main reservoir fluid pressure may flow fromthe main re.erv-oir M1 (not specifically shown) through the upper valve 32 of thedevice EPV through the pipe 33, check valve 34, pipe '35, to thecapacity reservoirlt' and the sylphon The pressure in the sylphon 36causes the valves 37 and 38 to be held in their lower position againstthe force of the spring 39, so that main reservoir pressure may flowfrom the main reservoir MR through pipes 40 and 41, valve 38, pipe 42,check valve 43. pipe 44 to the capacity reservoir R and also to thesylphon 45. With pressure existing in the sylphon 45 the valves 46 and47 are held in their lower position against the force of the spring 48,so that main reservoir pressure may also flow from tl e main reservoirMR through pipes 40 and 5O, through the valve 47, pipes 51 and 52, tothe large cylinc of the brake valve actuator EVA. This brake valveactuator and the engineers brake valve EBV with which it is associatedare more specifically described in the *iatent to Charles S. Bushnell,No. 1,628,- 454, granted May 10,1927;

V] hen the train, conventionally illustrated by the axle TR, passesfromone clear block into the next cl ar block the control relay CR maybede-energized for a short time by reason of the dead section associatedat the junction of two blocks, by reason of stagger joints, or the like.This de-energization of the control relay CR niay'cause momentaryde-energization of the device EPV, but by reason of the capacity of thereservoir R the de-energization of the device EPV will not causesuiiicient air to escape through the restrictedopening 34 of thecheck'valve 34 to permit actuation of the relay PR. In other words, theprovision of the restricted opening 34 and the reservoir R delaystheoperation of the pneumatic relay PR to the desired extent, as determinedby the volume of this rvoir and the area of this orifice 34 so as not tosoundthe whistle-W.:: If. the train is moving very'slowly the whistlemight possibly sound because of the reversing of relay PR,but'even ifthlSzShOlllfl happen the delay. imposed by the reservoir R and-therestricted opening- 48 of the check valve 43 would prevent operation ofthe device PBV. Also, the ball in'thecheck valve 34 is provided topermit quickchargingof the reservoir R Re-energization of the controlrelay CR always eiiects re-energization of the device EPV so long as thecontacts 29 of the stick air switch SAS are not opened, thus makingthe'device EPV a stick devicehaving a slow opening stickcontact 29. Y 1r 1 Audible signals. Upon entranceot a train into a caution or dangerblock the vcontrol relayfCR. is de-energized for a suiticient periodtocause the'pneumatic'relay PR'tooperate in response to venting pressurefrom the sylphon 36. This causes air pressure to flow from the reservoirB through the restricted orifice 43 -through the valve 37 tothewhistleWV. ,The volume of the reservoir R and the area of the orifice 43 are sochosen that the whistle WV is soundedfor, say livefseconds (orany othersuitable time interval) deemed sufficient timefor theengineer tomanifest his vigilance." All of the air'vented from the reservoir B maybe caused to flow to the whistle W or another atmospheric opening 59 maybe provided if desired. Theball in thecheck valve 43 is provided topermit quick re-charging of the reservoir R upon restoration ofthepneumatic relay ,PRto normal! Acknowledgment. The 1 sounding of thewhistle or audible signal W advises the engineer that he is to manifesthis vigilance by operating the handle 60 of the acknowledging valveAVito thefdotted position and back to the normal solid line position. Ifthe engineer operates the handle 60 in this manner,

air pressure'is first caused'to flow from the 1 favorable trafiicconditions ahead, and the trainwill be brought to a stop by the automainreservoir MR to the acknowledging reservoir and'is thenfcaused toflowfrom the acknowledging reservoir '61, through pipe 62, valveAV, pipe 63,valve 64 now in its raised position because of the deenergization ofrelay CR, pipe'65, to the acknowledging air switch AAS, thereby causingclosure of the contacts 66, and reapplication of current to the deviceEPV through a circuit readily traced in the drawingand including thewires 67 and 68. Upon the reapplication of current to the device EPVthis device EPV and the pneumatic relay PR will be restored to normalthus preventingoperation of the pneumatic brake valve PBV and anautomatic brake application. In order to require successivemanifestations of vigilance by the engineer, and in order to prevent theengineer misusing, as by tying down, the acknowledging device, the pipeis also'connected through a restricted orifice R0 to atmosphere whichdevice BO includes an adjustablevalve 7 O which is adjusted to providethe desired time intervalbetween successive acknowledging .acts andwhich is held in its adjusted position by a seal 71. In other words, the'sizefof the. orifice through the device R0 and the volume of theacknowledging reservoir 61 are so arranged that the air switch AAS isheld closed for, say two minutes (or any other. suitable interval oftime), after which the engineer is required to again operate the handle60 to its dotted position and back to its normal position to prevent abrake application. The engineer need of coursenot operate the handle 60until the device EPV has been de-energized and has caused thepneumaticrelay PR to respond and effect the sounding of the whistle W. V

The electrically operated valve EAV is employed to prevent the engineertaking advantage of the acknowledging device before the main relay GR isale-energized, and if desired this .valve EAV may be omitted.

Reset. If the engineer should become incapacitated orshould for someother reason not manifest his vigilance at all or should Will not onlycause operation of theengineers brake valve but Wlll also cause theopening of the contact 29 of the stick air switch SAS.

.As soon as this air switch has been operated to open its contact 29,the device EPV cannot be restored by closure of the contacts 6.6 inresponseto acknowledgment by the engineer, nor by restoration of thecontrol relay CR 'to normal in response to a change to matic brakeapplication as just explained. With the train broughtto-a stop theengineer or fireman may alight to the ground and depress the push buttonof the reset switch RS, which push button 75 is so located that it isonly accessible from the ground. Upon depression of the push button 75closing the contact 81, and providing the control relay GR is energizedto normal or with the relay CR deeneregized or reversely energizedandwith either the brakes applied and the contacts 76 closed or theacknowledging reservoir charged with the handle 60 in thenormal'position, the device EPV is i e-energized through oneofthe-following circuits: (1)

Wire 20, contact 21, wires 22 and 23 (2) wire 67, contact 66, wires 68and 23, (3) wire 77, contact 6, wire? 8 and then through the wire 24,normally closed contacts 25 of the reset switch ,RS,-wire 26winding ofthe device EPV, wires 27 and 80, normally open con tacts 81 of the resetswitch RS, wire 82 to the common return wire C connected to the otherside of he battery containing said terminal B. This re-energization ofthe device EPV eventually closes contact 29 of the air switch SAS afterwhich the push button 7 5 may be released. In this connection it isdesired to point out that the contacts 25 of the reset switch RS willnot open until after an interval of time as determined by suitableretarding means, such as the dash pct 79, after the push button has beendepressed, this in order to permit the circuit ust traced to be closedfor a suflicient interval of time to eii ect re-closure of the stickcontact 29 of the air switch SAS. The brake airswitch 13213 has itscontacts 7 6 closed when the en gine-and tender brakes are fully appliedand is provided so that no acknowledgment is required when the train isstandingon a siding or is in a round house with its engine arakesmanually applied. This brake air switch comprises a cylinder connectedto the brake cylinder and having a piston spring pressed to the positionshown to hold the contacts 76 open, which piston is operated to aposition to close contacts 76 when an adequate bralrc application hasbeen made. This 'fea ture also relieves the engineer of the duty ofwiring an acknowledging act when entering a caution block with thebrakes manually applied, at least until the train has been brought to astop, after which if the brakes are released acknowledgment is necessaryto prevent deenergization of the device EPV.

Applicant has therefore provided comparatively simple car-carriedapparatus in which a pneumatictime element device is employed to preventthe requirement of acknowled ment and prevent the sounding of theacknowledging warning signal W when a train passing over a dead section,has provided a pneumatic time element device for allowthe engineer apredetermined interval of time during which he may manifest hisvigilance by acknowledgment after the warning whistle W has started tosound, and has further provided a pneumatic time element device whichfixes the frequency at which the acknowledging act should be repeated,in combination with the necessary influence connnunicating and controlapparatus for controlling the pneumatic car-carried apparatus. Althoughthe system has been shown rather conventionally and many of the elelentsthereof have been shown rather specifically it is desired to beunderstood that he particular illustration of the invention has beenselected to facilitate disclosure of tie underlying principles thereof,and that the particular showing has not been selected for the purpose ofillustrating the scope of the invention, and it is further desired to beunderstood that various changes, modifications or additions may be madeto adapt the invention, to the particular system to which it is to beapplied, all without departing from the scope of the invention except asdemanded by the scope of the following claims. What I claim as new is:r 1. An automatic train control system comprising, a vehicle carriedcontrol relay con- .trolled in accordance with traffic conditions aheadof said vehicle, an electro-pneumatic valve, brake control meanscontrolled by said electro-pneumatic valve, contacts closed only whensaid brake control means is in its inactive condition, a circuit forsaid electropneumatic valve including said contacts, conenergized, meansfor shunting said latter contacts 1f the engineer has manifested hisv1g1lance, and other means for shunting said latter contacts if thebrakes have been man-.

ually applied.

2. An automatic train control system comprising, an electro-pneumaticbrake control means on a railway vehicle, including pneumaticallyoperated contacts controlled pneu-i matically by said electro-pneumaticmeans, a relay controlled in accordance vwith trafic conditions aheadotsaid Vehicle for controlling said electro-pn'eumatic brake control meansthrough a circuit including said pneumatically operated contacts, and asupplemental circuit for energizing said electropneumatic brake controlmeans including said pneumatically operated contacts and other contactsclosed only if the engineer manifests his vigilance at repeated time 7intervals.

brake control means including said pneumatically operated contacts andother contacts closed only if the engineer manifests his vigilance atrepeated time intervals, and adjustable means for determining the lengthof said time intervals.

4:. An automatic train control system comprising, an electro-pneumaticvalve on a railway vehicle including pneumatically operated contacts, arelay controlled in accordance with traffic conditions ahead of saidvehicle for controlling said electro-pneumatic valve through a circuitincluding said pneumatically operated contacts, and a supplementalcircuit for energizing said electropneumatic valve including saidpneumatically operated contacts and other contacts @80 tacts closed onlywhen said control relay is closed only if the engineer manifests hisvigilance at repeated time intervals, adjustable means for determiningthe length of said time intervals, and means for allowing anthorizedpersons only to change the adjustment of said adjustable means.

5. An automatic train control system com prising, a vehicle carriedcontrol relay normally. energized in response to current in the trackrails flowing in accordance with traiiic conditions ahead of saidvehicle, an electroneumatic valve, brake control means controlled bysaid electro-pneumatic valve, contacts closed only when said brakecontrol means is in its inactive condition, a circuit for saidelectro-pneumatic valve including said contacts, contacts closed onlywhen said control relay is energized, means for shunting said lattercontacts if the engineer has manifested his vigilance, and other meansfor shunting said latter contacts if the brakes have been manuallyapplied.

6. An automatic train control system con prising, an electro-pneumaticbrake control means on a railway vehicle, pneumatically operatedcontacts controlled pneumatically by said brake control means, a relaynormally energized in response to current in the track rails ahead ofsaid vehicle-for controlling said electro-pneumatic brake control meansthrough a circuit including said pneumatically operated contacts, and asupplemental circuit for energizing said electro-pneumatic brake controlmeans including said neumatically operated contacts and other contactsclosed only if the engineer manifests his vig ilance at repeated timeintervals.

7. An automatic train control systemcomprising, an electro-pneumaticbrake control means on a railway vehicle, pneumatically operatedcontacts controlled pneumatically by said brake control means, a relaynormally energized in response to'current flowing in the track railsahead of said vehicle for controlling said electro-pneumatic brakecontrol means through a circuit including said pneumatically operatedcontacts, a supplemental circuit for energizing said electrdpneumaticvalve including said pneumatically operated contacts and other contactsclosed only if the engineer manifests his vigilance at repeated timeintervals, andadjustable means for de termining the length of said timeintervals.

8. An automatic train control systemv comprising, an electro-pneumaticbrake control means on a railway vehicle including pneumaticallyoperated contacts, a relay controlled in accordance with traiiicconditions ahead of said vehicle and depending for its energization uponcurrent flowing in the track rails for controlling said electropneumaticvalve through a circuit including said pneumatically operated contacts,and a supplemental circuit for energizing said electro-pneumatic valveincluding-said pneuto said reservoir and at other times connectsaidreservoir to said cancelling means, adjustable means for venting fluidpressure from said cancelling means, and means for locking saidadjustable means, whereby the frequency of operation of said manuallyoperable means required to maintain said cancelling means active mayonly be adjusted by an authorized person.

10. An automatic train control system comprising, an electro-pneumaticbrake control means on a railway vehicle, pneumatically operatedcontacts controlled pneumatically by said brake control means, a relaynormally energized in response to current in the track rails ahead ofsaid vehicle for controlling said electro-pneumatlc brake control meansthrough a circuit including said pneumatically operated contacts, asupplemental circuit for energizing said electro-pneumatic brake controlmeans including said pneumatically operated contacts and other con tactsclosed only if the engineer manifests his vigilance at the repeated timeintervals, and another supplemental circuit for energizing saidelectro-pneumatic brake control means including contacts closed only ifthe brakes have been manually applied.

11. An acknowledging device comprising, cancelling means responsive topredeter mined pressure, a source of fluid pressure, a reservoir,manually operable-means for at times connecting said source of fluidpressure to said reservoir and at other times connecting said reservoirto said cancelling means, adjustable means for venting fluid pressurefrom said cancelling means, and means for locking said adjustable meansby a breakable seal, whereby the frequency of operation of said manuallyoperable means required to maintain said cancelling means active mayonly be adjusted without penalty by an authorized person.

12. An automatic train control system comprising, a car-carried relaycontrolled in accordance with traffic conditions ahead of the car, anelectro-pneumatic valve, pneumatic apparatus pneumatically controlled bysaid electro-pneumatic valve having contacts associated therewith whichare opened a predetermined time after said electro-pneumatic valve. isdeenergized, a circuit for energizing said electro-pneumatic valveincluding contacts of said relay and the contacts of said pneumaticapparatus in series, and an auxiliary circuit for said electro-pneumaticvalve including the contacts of said pneu- Inatic apparatus and contactsclosed only When the brakes are fully applied in series.

In testimony whereof I aflix my signature.

/ WADE H. REIOHARD.

